Chemical Welding of the Electrode-Electrolyte Interface by Zn-Metal-Initiated In Situ Gelation for Ultralong-Life Zn-Ion Batteries.

Abstract

A compatible and robust electrode-electrolyte interface is favorable in resolving the severe dendritic growth and side reactions of aqueous Zn-ion batteries toward commercial-standard lifespan and charging-discharging rate. Herein, a chemical welding strategy through insitu construction of a gel electrolyte that enables Zn-ion batteries to achieve ultralong life and reversibility is reported. The gel electrolyte is spontaneously formed on the Zn anode surface by redox polymerization with the initiation of Zn metal. The direct participation of the Zn anode in the chemical synthesis of the gel electrolyte brings a well-bonded and water-poor electrode-electrolyte interface, which not only alleviates side reactions but also enables preferential (002) Zn deposition. The insitu symmetric cell thus prepared delivers an ultralong lifespan of 5100h (>212days), and a hybrid capacitor with the insitu electrolyte runs smoothly over 40000cycles at 20Ag-1 . Even at an ultrahigh current density of 40mAcm-2 and capacity of 40mAhcm-2 , the cell still operates stably for 240h, alongside a high Zn utilization with 87% depth of discharge. The insitu gel electrolyte integrating robust interface and preparation of all-in-one cells demonstrate a commercializable path for aqueous Zn-storage devices.